GLP1R and Parkinson disease: Apart from its glucose lowering effect, GLP-1 receptor stimulation has been investigated in animal models of PD and shown to increase neurogenesis (Bertilsson et al. 2008), to arrest and possible reverse nigrostriatal damage (Harkavyi et al. 2008), and to protect dopaminergic neurons from neurodegeneration (Li et al. 2009).